The invention relates to an electrical plug connection with a plug receiver and a plug pin, especially a plug pin of round cross-section, the plug receiver having a receiving chamber and an axially compressible coil spring having individual turns being disposed in the receiving chamber.
A known electrical plug connection of this type has a contact piece axially displaceable in the receiving chamber and is located ahead of the coil spring in the direction of insertion. The plug pin enters into end face electrical contact with the contact piece in an insertion operation. It is further known to provide a tubular plug receiver, onto which, on an outer surface, a coil spring is pushed on, one turn of the coil spring penetrating secant-like into the interior of the plug receiver through an opening in the plug receiver. In an insertion operation, the plug pin is pressed against an inner surface of the plug receiver by the turn which extends secant-like, so that in this manner the desired electrical contact comes about.
Each of these known plug connections is unsatisfactory in different respects. In regard to the axially displaceable contact piece, an electrical contact between the contact piece and the plug pin is achieved only on a comparatively very small surface. There results, on account of the small, point-form contacting surface, relatively high wear on the contacting surfaces, because flashover and contact-breaking sparks form precisely in the region of these surfaces. In the version with the spring turn extending secant-like, relatively high friction is produced between the plug pin and the inner surface of the plug receiver. The wear is especially great in this case when insertion and withdrawal takes place under electrical load. The mechanical wear is greatly promoted by the formation of contact-breaking and flashover sparks in the contact region. Having regard to the above-described state of the art, it is seen as a technical problem for the invention to provide an electrical plug connection in which, on the one hand, there occurs the least possible wear even with frequent insertion cycles, while on the other hand, the plugging force does not become too high, all this with good and reliable electrical contact.